As to recent mobile phones, a model of a mobile phone having a camera module embedded therein has been dominant. Such a camera module needs to be embedded in the mobile phone, and therefore has a greater demand for miniaturization and weight reduction compared with a digital camera.
Also, there have been an increasing number of examples in which a camera module of a type exhibiting an autofocus (AF) function by a lens driving device is mounted on electronic equipment such as a mobile phone. Examples of the lens driving device include various types such as a type using a stepper motor, a type using a piezoelectric element, and a type using a VCM (Voice Coil Motor), which have already been distributed on the market.
Meanwhile, now that such a camera module having the autofocus function has become a standard, an image stabilizer function is becoming a focus of attention as a next distinctive function. Although the image stabilizer function has been widely adopted for digital cameras and camcorders, there have been only a few models of mobile phones adopting the image stabilizer function, since there is a problem of a size. However, a new structure of an image stabilization mechanism, which allows miniaturization and thinning, has been suggested, and it is expected that a mobile-phone-specified camera module having the image stabilizer function mounted thereon will be more widespread in years to come.
As the image stabilization mechanism, PTL 1 describes an image stabilization device of a lens-shift system or a sensor-shift system. In an imaging unit described in PTL 1, the image stabilization device which drives a lens or an image sensor in directions of two axes perpendicular to an optical axis direction is arranged in a stacked manner on a camera module having an imaging block which drives a lens in the optical axis direction. Note that, the lens in the imaging block is not driven in the directions of the two axes perpendicular to the optical axis direction.
Moreover, PTL 2 describes an example of an image stabilization autofocus camera module of a barrel-shift system, which drives a focus portion including a lens portion and a second driving portion which drives the lens portion in an optical axis direction in the optical axis direction and directions of two axes perpendicular to the optical axis direction. In the camera module described in PTL 2, the focus portion is supported with respect to a base part by four suspension wires. Image stabilization is achieved when the focus portion is driven in the directions of the two axes perpendicular to the optical axis direction.